This proposal seeks to continue a Clinical Hematology Career Development Program in benign hematology and transfusion medicine at the Johns Hopkins Medical Institutions (JHMI). The next generation of clinical researchers in benign hematology and transfusion medicine will need to include individuals with the skills, attitudes, early research training and experience to capitalize on rapidly developing progress in these disciplines. In developing this program, we will use established research infrastructure, including free-standing Divisions of Hematology in Pediatrics, Internal Medicine and Transfusion Medicine that are dedicated to the care and study of benign hematologic disorders, as well as our Graduate Training Program in Clinical Investigation (GTPCI) at the Johns Hopkins University School of Medicine and Johns Hopkins University Bloomberg School of Public Health. Our specific aims are: a) To continue to identify, recruit, train and develop creative and successful clinical investigators, with the capability to interact with, participate in, and lead multidisciplinary teams involved in clinical research, address complex problems and become national leaders in pediatric, adolescent and adult benign hematology and transfusion medicine; b) To provide trainees with the requisite skills, knowledge, attitude and experience for successful academic careers in clinical research in these areas. This training will include exposure to national and international leaders and curriculum in the multiple disciplines necessary for successful clinical research, including benign hematology, transfusion medicine, clinical trials design, epidemiology, statistics, research ethics and human subjects protection; c) To provide a rich mentoring environment. We will integrate multiple research resources and investigators available at the JHMI to provide optimal exposure of trainees to research experiences and training. We will continue to focus our efforts in six areas where we feel there is particular strength within our institution: bone marrow failure and stem cell biology, sickle cel disease (SCD), myeloproliferative disorders, transfusion medicine, outcomes research and genetics. We will work with several established investigators and mentors to develop a structured curriculum in benign hematology and strong mentored research experiences for trainees. Careful and extensive mentoring will be the cornerstone of these efforts, with exposure to cutting edge research experiences. Through this program, we ultimately aim to provide a cadre of clinical researchers, who will become creative, independent investigators, care for patients and assume leadership roles in benign clinical hematology.